code: def _shutdown(self):
      # attempts sending one last heartbeat
      self._heartbeat()
  
file_path: metaflow/metaflow/metadata/heartbeat.py
imports: import time
  import requests
  import json
  from threading import Thread
  from metaflow.sidecar import MessageTypes, Message
  from metaflow.metaflow_config import SERVICE_HEADERS
  from metaflow.exception import MetaflowException
label_desc: Use image node_id 6 for calling the MetadataHeartBeat obj's underlying member method code with example usage: obj._shutdown() without return types